Purity: Method of Performing Tayammum on a Corpse
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 557:
Someone who performs tayammum on a corpse must strike his own palms on the earth and then wipe them on the face and the back of the hands of the corpse; and if it is possible, the recommended precaution is to perform tayammum using the hands of the corpse.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)